Genetic Variation: Now We’re Gonna Have AnnnnnTs…

As I arrived home the other evening I was greeted with a bizarre question: “Did you know that only some people can smell ants?!”

I didn’t. But it got me thinking, what are some interesting genetic differences in people? Are there other strange things that only some of us can or can’t do?

Well for starters there are hereditary diseases, thousands of them. A particularly interesting one is haemophilia, a disorder that impairs the body’s ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken. Not that the disease is that interesting symptoms-wise, but haemophilia figured prominently in the history of European royalty in the 19th and 20th centuries. Back in the old days, fancy people married fancy people, in order to keep control of the crown. As a result, Britain’s Queen Victoria, through two of her five daughters (Princess Alice and Princess Beatrice), passed the mutation to various royal houses across the continent, including the royal families of Spain, Germany and Russia. Victoria’s son Prince Leopold, Duke of Albany suffered from the disease. For this reason, haemophilia was once popularly called “the royal disease.” Sadly, no living member of the present or past reigning dynasties of Europe is known to have symptoms of haemophilia or is believed to carry the gene for it.

Most Chinese people lack, in one of the rare cases of this type, a beneficial mutation that enables others to eat milk and dairy products. Chinese distaste for milk was thought to be cultural until the 1960s, when lactose intolerance was found in many populations in East and South East Asia, and also in parts of Africa. Within the past 10,000 years, the beneficial mutation spread only where dairy farming was the norm.

In 1940, the famous geneticist Alfred Sturtevant noted that about 70 per cent of people of European ancestry are able to roll up the lateral edges of the tongue, while the remaining 30 per cent were unable to do so. It may be due to a single gene, with the ability to roll the tongue a dominant trait and the lack of tongue rolling ability being a recessive trait. However, there is some question about the inheritance of tongue rolling. Recent studies have shown that around 30 per cent of identical twins do not share the trait.

Ants have the distinct of odour of formic acid, but only some people can smell them, you’ll definitely know if you can. People with more complex olfactory systems end up being the perfume connoisseurs that you always assumed to be full of shit.